1. Field of the Invention
The invention relates to a single-phase reluctance motor, particularly a reluctance motor comprising a stationary member (stator) and a movable member (rotor) which is movable relative to said stationary member, an air gap being formed between said members, one member comprising a magnetically permeable ferromagnetic body having salient pole parts and the other member comprising an electrically excitable ferromagnetic body having salient pole parts.
2. Description of the Related Art
Reluctance motors basically comprise a stationary member (stator) and a movable member (rotor), the stator being provided with a single-phase or polyphase electrical winding which produces a magnetic flux through the stator and the rotor when a current is passed through this winding. The rotor and the stator consist of ferromagnetic materials which are readily magnetisable up to a certain maximum induction, the saturation induction. Initially the induction in the material increases rapidly in response to an increasing current in the electrical winding and subsequently it increases only slightly. This effect is called saturation. The construction of a single-phase motor is very simple.
The magnetic forces produced under the influence of the current cause the rotor to be rotated towards a position in which the rotor and stator teeth are situated as closely as possible opposite one another, which is the so-called aligned position in which the stored magnetic energy is maximal. However, the initial direction of rotation of this single-phase motor is dependent on the initial position of the rotor and, if the motor is already in the aligned position, it will not be rotated at all. The motor will then fail to start.
In order to avoid this, such motors are provided either with an auxiliary winding or with a holding magnet, which ensure that the rotor always remains in or can be moved to (auxiliary winding) a given offset position relative to the aligned position.